To make a bootable floppy in XP, put a blank floppy in the drive, open Windows Explorer> right click on the floppy drive> format> at the bottom of that next pop-up window, tick the option 'Create an MS-DOS Startup disk.' This will erase everything on the diskette and make it bootable. Then you can copy your flashing utility and other necessary files to it for the flashing operation. Be sure to read those (flashing) instructions carefully at your motherboard's bios download site before you flash - DON'T skim read - follow the instructions to the letter.